Gas heater



' L. C. SMITH July 18, 1933.

GAS HEATER Filed Aug. 8, 1952 5 Sheets-Sheet l L. c. SMITH July 18, 1933.

GAS HEATER Filed Aug. 8, 1932 3 SheetsSheet 3 5 4/; AffOr/JQ J Patented July 18, 1933 UNITED STATES.

PATENT OFFICE LEO G. SMITH, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO SMITH SYSTEM HEATING 00., OF MINNEAPOLIS, MINNESOTA, A CORPORATION OF MINNESOTA GAS HEATER Application filed August 8, 1932. Serial No. 627,839.

My invention provides a simple and highly eflicient gas heater adapted for use in rural school houses, churches and elsewhere. The

a term gas is used in a broad sense and may be natural gas, canned gas, hydro-carbon side or fresh air and complete contact thereof 7 with the radiating surfaces of the flues and other parts of the heater, complete combustion in proportion to the volume of air to be heated, longest and most eflicient travel of the products of combustion against the tubes and other walls that conduct the air through the heater, and generally stated, the highest possible heating efficiency with a minimum of as.

b In accomplishing the above results, I have provided an important and novel relative arrangement of air tubes and interposed baffles, whereby the products of oombustlon from the burner are deflected or caused to travel alternately upward and downward against and in good heat exchange contact with the flue surfaces, and are caused to continue the heat exchange action until the flue or stack outlet temperature has been reduced to a minimum.

A commercial heater involving the invention, is illustrated'in the accompanying drawings wherein like characters indicate like parts throughout the severalviews.

Referring to the drawings 1.

Fig. 1 is a perspective with some parts broken away, some parts removed and some parts diagrammatically shown by dotted lines- Fig. 2 is a vertical section taken through the heater approximately on the line 2-2 of Fig. 3; and

Fig. 3 is a horizontal section taken through the heater on the line 3-3 of Fig. 2.

Preferably, this heater is rectangular in horizontal section and is mountedon a rectangular base 4 having corner projections 5 to which supporting legs 6 are secured Secured upon and projecting upward from the legs 6 is a rectangular outer casing preferably a double-wall casing 7 that is open at its top except the perforated or grilled cover 8, through which latter the air will freely pass. A

Rigidlysecured on the rectangular base 1 and rising therefrom within the outer shell 7, is a rectangular inner shell 9. Preferably, the parts 7 and 9 are of sheet metal. The shells 7 and 9 are spaced to afford a large free air passage 10 entirely around the inner shell, which latter terminates above the top of the shell 7 to form an upper air commingling chamber 11. The top of the inner shell 9 is closed by a sheet-like head 12.

Located within the lower portion of the inner shell 9 is a box-like structure 13 that is joined to the lower portion of the rear wall thereof and divides the lower portion of the interior of said shell 9 into a combustion chamber 14 and an air intake chamber 15. A plurality of large air tubes 16 extend from ports in the top of the box-like partition 13, to ports formed in the head 12 and thus connect the air intake chamber to the air commingling'chamber 11. The bottom of the chamber 14 is in communication with an air intake box 17 which, in this preferred arrangement, leads from the exterior of the room for the intake of fresh air, and as shown, is provided with large air intake ports 18 that open from the room and are arranged to be opened or closed more or less by dampers 19. The upper portion of the inner shell 9 is connected to a chimney flue 20 for the outlet of the products of combustion.

The gas burner is located in the lower portion of the combustion chamber 14 and just above an air intake box 21, which as shown, depends from the base 4. This burner so far as the major features of this invention are concerned, may take various forms but, as shown, it comprises a hollow head 22 which receives gas or combustible vapor from a supply pipe 23 and is provided with a plurality of discharge nipples 24. The regulation of the supply of air to this burner may be adjusted to correspond to the amount-of air heated or other varying conditions by a baflle plate that is secured to the air intake box 21 by machine screws or bolts 26 and is arranged to be variably spaced. therefrom by shims. By reference to 2, it will be noted that the box-lil-te structure 13 afiords an air intake chamber 15 and is forwardly bulged so as to join with the front row of tubes 16 and to overlie the burner so that it will be subject to direct and intense heat from the burner.

Associated with the air tubes 16 are baffies plates 28, 29 and 30. 28 and are extended downward from the head plate 12 but terminate above the top of the partition 13, but the ballie 29 extends up- Ward from the top of said partition 13 and terminates below said plate 12. In horizontal section, the bailie plates 28, 29 and 30 are corrugated by alternated wall-forming portions that are preferably bent at right angles and are arranged to tangentially contact with the adjacent tubes. The said V-shaped corrugations correspond in number to the number of the adjacent tubes so that each tube contacts with two walls of each corrugation, but free or unobstructed passages are left for the freetravel of the products of combustion first upward, then downward, and again upward in contact with the air tubes. The alternated upward and downward travel of the products of combustion from the combustion chamber 1a is indicated by arrows marked 011 Figs. 1 and 2. Fig. 3 illustrates the amount of clearance between tubes and balile plates. The ballie plates 28 and 29 direct the products of combustion against the first row of air tubes; the baffle plates 29 and 30 direct the products of combustion against the second or intermediate row of air tubes; and thebaifie 30 and rear wall of the inner shell 9 direct the products of combustion to the rear row of air tubes and to the outlet flue or pipe 20. Of course, the number of tubes and bafiles can be varied. This arrangement of tubes, baffles and shell. or casing keeps the products of combustion in contact with the tubes until a maximum amount of heat has been transferred to the air passed through the tubes and around the inner casing. The baffle 28, being spaced from the front wall of the inner shell 9 forms a chamber 31, see Fig. 2, which cages part of the products of combustion and. causes the same to radiate heat into the main air passage 10. Of course, all the walls of the inner shell 9 will be kept hot and will radiate heat into the surrounding air passage 10. Essentially, there will be a restricted circulation of hot gases within the chamber 31', to wit: a circulation sufiicient to properly distribute the heat at the front of the stove, and without the partition 28 the heat at the frontof the stove might be excessive. Contact between baffle plates and The baflie plates tubes increases the conductivity and hence the heat exchange capacity.

The air from the room only will be circulated through the main air passage 10. When both dampers 19 are moved to positions to close the ports 18, only fresh air from the exterior of the room or building will be delivered into the air intake box or chamber 15 I and from thence through the air tube 16. If

both dampers 19 be moved into aligned positions, the supply of fresh air will be nearly or quite out OK, and only air from the room will be drawn in through the ports 18. Obviously, by adjustments of the dampers 19, the proportion of the amount of fresh air drzlrwn into the heater may be regulated at wi l.

The casing 7 in its front wall is shown as provided with an opening normally closed by a door 33, and the front wall of the inner shell 9 with an opening normally closed by a door 34. These doors when opened, afford access to the burner.

The baffle plate 25, it will be noted, is located at the bottom of the box 21 that'depends belowthe burner. This provides a marginal air passage between the bafiie and the bottom of the box and is located so far below the burner that wind blasts will not disturb the flame in the burner and will notblow the burner out even under exceptional conditions. Moreover, the air thus introduced will first enter the box 21 and will then be evenly distributed around and through the air passages of the burner so that a very even and complete combustion of the gas is insured.

In actual commercial manufacture and use, the heater herein dISClOSGd'ElDd claimed has been found to be highly efiicient for the purtion. Of course. the particular structure illustrated is capable of various modifications within the scope of the invention herein disclosed and claimed.

What I claim is:

1. In a heater. a casing for products of combustion. air-circulating tubes within said casing. and corrugated baflies arranged in staggered relation within said casing with the corrugations thereof paralleing said tubes and extending substantially tangentially to sides of said tubes. whereby to provide a tortuous channel for the products of combustion through which the tubes extend in heat radiating relation to said bafiies.

2. The structure d e ined in cla m 1 in which the corrugations of said baffles are V-shaped in horizontal cross-section and are extended to correspond to the spacing of the adjacent tubes.

3. In a heater, an outer casing, an inner casing spaced therefrom to afford an intervening air passage, a combustion chamber and an air intake chamber in the lower portion of said. inner casing, vertical air tubes extending from said air intake chamber through the top of said inner casing, a burn er in said combustion chamber, vertical baffles associated with said air tubes and arranged in staggered relation within said in nor casing to cause the products of combustion to travel alternately upward and downward to contact with said tubes, said bafiies being formed with V-shaped corrugations arranged substantially in contact with the adjacent tubes, the said corrugations correin said chamber.

LEO C. SMITH. 

